In condominiums and apartment buildings in which a plurality of owners or tenants use a common entrance, it is conventional to provide at this common entrance a lockable door. Only the owners or tenants residing in the condominium or apartment building are given keys to the lock on the door, which thus serves to exclude others from entering the building, thus giving greater security to the owners or tenants. To enable the owners or tenants to admit visitors without having to leave their apartments, the door is usually provided with a remote control device which enables the owners or tenants to unlock the door without leaving their apartments, after they have ascertained the identity of the visitors by means of an intercom or other similar device.
In order that the aforementioned lockable door may provide significant security to the owners or tenants within the building, it is necessary to provide the door with an automatic door closer so that it cannot be left open either accidentally or deliberately. However, conventional automatic door closers, which close the door as soon as it is released, pose problems when an owner or tenant wishes to make a number of trips through the door within a short period of time (for example, when several trips are necessary in order to unload a large quantity of groceries from an automobile) or when the owner or tenant wishes to hold the door open for a brief interval (for example, in order to maneuver a baby carriage or a bulky piece of furniture through the door). Because it is difficult in these circumstances to hold the door open manually, the owners or tenants tend to latch or wedge the door in its open position and even after they have passed through the door their hands are fully occupied so that they cannot unlatch or remove the wedge from the door at that time. By the time they have reached their apartments, the owners or tenants may have forgotten that they have left the door open or may be too lazy to make a long trip back in order to close it. This of course completely destroys the security value of the door.
There is thus a need for apparatus capable of temporarily holding a door open so that people can pass through the door without hindrance during a short period, but which permits the door to close under the action of an automatic door closer after a short period has elapsed. The invention provides such apparatus.